I generally shy away from tofu at restaurants because I don't like it when it's used a meat substitute. It's sad to think that tofu is almost an afterthought and added only to beef up a dish (I also have to confess that I just don't like firm tofu). But when the tofu is the main event, it's an entirely different story. Agedashi tofu (揚げ出し豆腐) lets the tofu shine. The crisp exterior of the deep fried tofu absorbs the subtle sweet soy dashi and the warm tofu becomes extra silky and melt-in-your-mouth soft in this classic Japanese dish. And the best part is, you really only need tofu plus some pantry items which you probably already have if Japanese cuisine is part of your repertoire.
I could never get agedashi tofu right at home, which is why I used to order it at restaurants. I thought it required the industrial deep fryer to crisp up the tofu without letting the skin fall right off. But with some simple tips from my mother it has become an easy side dish for a weeknight dinner. The trick is to take the extra step in removing most of the moisture from the tofu. Start off with soft tofu (if you buy the vitasoy brand, the multi-use tofu is my favorite) and cut into large bite sized cubes. Then place the cubes on a paper towel (I used newspaper as well for extra absorption) and place a flat object to gently press the tofu (in this case, a small cutting board).
Let the tofu sit under the press for a good hour or so (you can prep the dashi broth and garnishes while you wait or make your main dish). Once the pressing is finished, the tofu should look a little shriveled. This is exactly what you're looking for. Don't worry, it won't taste dry there is so much water content in tofu to go around.
Once the crucial preparatory step is done, we can move along to the frying. The batter is simple: just potato starch. It's a little bit harder to find than corn starch but it does allow for a thinner, crispier skin. Also, I find potato starch to be more neutral and a better thickener than corn starch. Dredge the tofu in potato starch and pat off the excess.
Heat up a cast iron, wok, or frying pan with fresh canola oil to about 350-375°F. If you don’t have a thermometer to check, stick a wooden spoon in the oil and you should see small bubbles forming around the spoon. Gently place a few cubes of tofu into the oil being careful not to overcrowd. Crowding the pan will lower the temperature of the oil too drastically for the tofu to crisp up. Move the tofu around in the beginning to make sure it doesn't stick to the pan and then let it sit until you start to see the lower half turn golden brown. Once it develops a crispy skin, flip the tofu gently. The first step in removing the moisture as well as letting the tofu develop the skin will help this step tremendously.
If you've already made the dashi broth and prepped the garnishes while pressing the tofu, you're ready to plate and eat!